Recently with the weather getting colder (I am from utah) my ABS light came on in my 2002 V6 4.0 SOHC, with the code C1230 which indicates the rear wheel speed sensor which sits atop the rear differential. I went to my local parts store and picked up the part (around $27) and replaced it, it was very simple seeing as all it takes is one bolt. I had the codes cleared and went to drive my truck today and the ABS light was still burning strong. I once again had the codes read and it is still reading C1230. Any ideas as to what is still causing that code to be thrown? I've checked the connections around and even tested the voltage going to the switch and all of it checks out. Any help is appreciated. Thanks.

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1994 Ford Ranger xlt extended cab. V6 3.0.